crush up a few dozen white cedar berries and chuck them into any aggregations you see, that'll fix em
I recon a couple of small bullsharks would chew thru a few of the bigger Talapia.
I can just see the headlines....shark sighted in Inala Waters...Ops sorry Forest Lake.
Then you could have big game fishing in the western suburbs.
Yeh Talapia are commercialy farmed overseas too.
Perhaps a few Eels would redress the imbalance..they will take on just about anything.
cheers
Its the details, those little details, that make the difference.